Portable electronic devices may include one or more batteries that may require recharging from time to time. Such devices may include electric vehicles, cell phones, smart phones, tablet computers, laptop computers, wearable devices, navigation devices, sports devices, health analysis devices, medical data devices, location tracking devices, accessory devices, home appliances, peripheral input devices, remote control devices, and so on.
Some batteries may recharge wirelessly. For instance, a wireless power transfer system can include an electronic device configured to accept inductive power and a transmitter adapted to produce inductive power. In these systems, a transmit coil within the transmitter may produce an electromagnetic flux that induces a current within a receive coil of the electronic device. The induced current may be used to replenish the charge of a rechargeable battery within the electronic device.
In many cases, change in input impedance may decrease an efficiency of power transfer between the transmitter and receiver.
Accordingly, there may be a present need for an inductive power transfer system with improved tolerance for changes in input impedance of the inductive power receiver.